| Autor: |
Anyanwu MU; Department of Veterinary Microbiology and Immunology, University of Nigeria, Nsukka 400001, Nigeria.; Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, Johannesburg 2092, South Africa., Ikenna-Ezeh NH; Department of Veterinary Microbiology and Immunology, University of Nigeria, Nsukka 400001, Nigeria., Okafor SC; Department of Veterinary Pathology, University of Nigeria, Nsukka 400001, Nigeria., Ezemuoka CF; Department of Veterinary Microbiology and Immunology, University of Nigeria, Nsukka 400001, Nigeria., Nwobi OC; Department of Veterinary Public Health and Preventive Medicine, University of Nigeria, Nsukka 400001, Nigeria., Ogunniran TM; Department of Veterinary Medicine, University of Nigeria, Nsukka 400001, Nigeria., Obodoechi LO; Department of Veterinary Public Health and Preventive Medicine, University of Nigeria, Nsukka 400001, Nigeria., Okorie-Kanu OJ; Department of Veterinary Public Health and Preventive Medicine, University of Nigeria, Nsukka 400001, Nigeria., Mgbeahuruike AC; Department of Veterinary Microbiology and Immunology, University of Nigeria, Nsukka 400001, Nigeria., Okosi IR; National Veterinary Research Institute, Vom 930001, Nigeria., Jaja IF; Department of Livestock and Pasture Science, University of Fort Hare, Alice 5700, South Africa. |
| Abstrakt: |
Background: Frequent use of colistin (COL) and tetracyclines in the Nigerian poultry sector potentially triggers bacterial resistance against COL and tigecycline (TIG), which are last-line antibiotics used to treat multidrug-resistant infections. Aim/Objectives: This study aimed to isolate COL- and TIG-resistant E . coli from commercial day-old chicks distributed to poultry farmers in Nsukka Southeastern Nigeria, assess the production of extended-spectrum β-lactamase (ESBL) and carbapenemase by the isolates, and establish their pathogenic potentials. Materials and Methods: Non-duplicate cloacal swabs were systematically collected from 250 randomly selected day-old chicks. MacConkey agar with 1 µg/mL of COL and 16 µg/mL of tetracycline was used for the isolation of putative COL- and tetracycline-resistant E . coli , respectively. E . coli isolates were confirmed biochemically using the API20E Gram-negative identification kit and molecularly by polymerase chain reaction targeting the uidA gene. Phenotypic COL resistance was established using COL agar and COL disc elution tests, while TIG insusceptibility was determined with disc diffusion. ESBL and carbapenemase production was assessed by double-disc synergy and modified carbapenem inactivation methods, respectively. Pathogenic potentials were determined using phenotypic methods. Results: COL- and TIG-resistant E . coli was recovered from 95 (38.0%) and 62 (24.8%) swabs from the 250 chicks, respectively. None of the isolates were potential ESBL or carbapenemase producers. The COL-resistant isolates displayed pathogenic potentials such as biofilm formation, haemagglutination, cell surface hydrophobicity, surface layer, and gelatinase activities at rates of 30.7%, 8.4%, 33.7%, 23.5%, and 17.6%, respectively. Meanwhile, the TIG-resistant isolates exhibited their respective potentials at rates of 47.0%, 21.0%, 35.5%, 58.1%, and 43.6%. Red, dry, and rough (RDAR) was the predominant curli fimbriae, and the cellulose morphotype portrayed by both the COL- and TIG-unsusceptible potential biofilm-producing isolates. Conclusions: This study demonstrates that a significant percentage of commercial day-old chicks distributed to farmers in Nsukka, southeastern Nigeria, are colonized by potentially pathogenic COL- and TIG-resistant E . coli , which could spread to humans and the environment. |
